Crystal detector for wireless telephony and telegraphy



Jan. 26 1926.

' 1,571,020 W. D. MCGOWAN E CRYSTAL DETECTOR FOR WIRELESS TELEPHONY ANDTELEGRAPHY Filed Sept. 16, 1922 2 Sheets-Sheet 1 INVENTOR.

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Jan. 26,1926. v 1,571,020

W O. M GOWAN CRYSTAL DETECTOR FOR WIRELESS TELEPHONY AND TELEGRAPH!Filed Sept. 16, 1922 2 Sheets-Sheet 2 INVENTOR. 7443. M Gawain A TTORNEY.

Patented Jan. 26, 1926.

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days: Decreases son wrnnnnss tnnniirrioivr Asmsmeanaa Application filedSeptember 16,1922. "serial as. 538,609.

T'o all whom 71$ may concern:

Be it known that I, WILLIAM D. Mo- GowAnj, a citizen ofth'e UnitedStates, and resident of Jersey City, in the county of Hudson and Stateof New Jersey, have invented certain new and useful Improvements inCrystal Detectors for Wireless Telephony and 'llelegraphy, of which thefollowing is a specification.v

The present invention relates to crystal or mineral detectors for radioor wireless telephony and telegraphy.

Crystal or mineral detectors now in common use employ an adjustablecontact point consisting of a single wire conductor and a fixed crystalor mineral element having but one of its sides positioned for contactwith the wire. These devices require frequent and fine adjustment inorder to make contact between the wire and the sensitive part of themineral element, which contact is frequently accidentally broken, byjarring of the instrument, and continuity of the message is interrupted.

My invention has for its object the pro vision of novel means forovercoming these objectionable features; further objects being toprovide a device of the character named which is simple in constructionand susceptible of quick adjustment; which is adapted for utilizing allsurface parts of a crystal or mineral element and which, when adjustedstays put and is capable of withstanding shocks; a still further objectis to provide means for protecting the crystal or mineral element fromdust and atmospheric influences.

In carrying out my invention I provide two slidably and rotatablyadjustable conductor-members having respectively a multiplicity ofyielding contact points, means for mounting said members, spring-meansfor holding said members in arbitrarily set relation, and means forenclosing a mineral or crystal element, all as hereinafter fullydescribed and specifically set forth in the appended claims.

In the accompanying drawings forming part ,of this specification. Figure1 is a plan view illustrating an embodiment of my improvement;

Fig. 2 is a side view;

Fig. 3 is an inverted plan view;

Fig. 4 is a longitudinal sectional View taken on the line er Fig. 1.

Fig. '5 is a cross sectional view thel'ine 55 of Fig. 1;

Fig. '6 isa'nend view'of oneof thec'o'ntact members; and I Fig. '7 is aside View thereof.

In the drawings, ;1 and 2 indicate cylindrical bearings which arecomposed fof'any suitable metal and are mounted on a block or base '3,of adaptable insulating material, by means of screws 4 and 5-, the screw4 being in electrical connection with a binding post 6, by means of ametal plate 7 and screw '8, andthe screw 5 in electrical connection with'abinding post 9, by means of a plate 10 and screw 11.

Connecting the inner ends of the cylinders 1 and 2 is a transparentglass tube 12 of the same inner diameter or bore as said cylinders,whereby the contact members hereinafter described may have free slidingmovement.

The contact members comprise, respectively, a resilient metal tube 13havin fixed in its outer end a plug 14 in which is lmbedded the outerends of the strands of a brush-like conductor 15 which is composed of amultiplicity of strands of fine wire of graduated lengths, whereby theprojecting or contact end of the brush is of approximately truncatedcone shape, as shown in Fig. 7 of the drawings, a knob 16 of insulatingmaterial being fixed around the outer end of the tube 13, whereby thecontact member may be manually manipulated. The tube 13 is composed of asheet of resilient metal havin overlapping edges which are fixed withinthe knob 16 and around the plug 14- adjacent its outer end part, aspring-yielding tongue 17 being provided for holding the contact membersin arbitrarily set position within their respective cylindrical bearings1 and 2.

It is manifest that by employing a detector of the character described afragment of crystal or mineral element, as a, may be readilymanipulatedby means of the slidably and rotatably adjustable contactmembers until the sensitive parts of the mineral element are inelectrical contact with the ends of the conductor brushes 15 which,owing to the yielding nature of their contact ends, maintain the contactand obviate taken on liability of having the same broken by jarring ofthe instrument.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. In a device of the character described, two spaced cylindricalelectro-conductive bearings, a cylindrical insulating member connectingthe bearings, an electro-conductive brush support slidable within eachbearing and a plurality of resilient electro-conductive brush bristlescarried by each brush support inwardly of the device abuttable upon afreely movable crystal detector.

2. In a device of the character described, a cylindrical holdercomprising two spaced cylindrical electro-conductive members connectedtogether by a non-conductive cylindrical member, a slidably movableconductive brush support within each spaced cylinder, a plurality ofresilient electro-conductive bristles carried by each brush supportwithin the device and a freely movable crystal detector within thedevice abuttable upon both sets of bristles.

3. In a device of the character described, a cylindrical holdercomprising two spaced cylindrical electro-conductive members connectedtogether by a non-conductive cylindrical member, a slidably movableconductive brush support within each spaced cylinder, a plurality ofwire bristles carried by each brush support Within the device, a freelymovable crystal detector Within the device abuttable upon both sets ofbristles and means for maintaining the brush supports in anypredetermined position Within the supports.

4:. In a device of the character described, a cylindrical holdercomprising two spaced cylindrical electro-conductive membersconnected-together by a non-conductive cylindrical member, a slidablymovable conductive brush support Within each spaced cylinder, aplurallty of Wire bristles carried by each brush support within thedevice, a freely movable crystal detector Within the device abuttableupon both sets of bristles and spring means for maintaining the brushsupports in any predetermined position within the supports.

Signed at New York, in the county of New York and State of New York,this 1st day of August A. D. 1922.

WILLIAM D. MoGOWAN.

